/**
 * Craeted with IntelliJ IDEA.
 * Description:
 * User:23687
 * Date:2024-09-22
 * Time:12:40
 */
import java.util.Scanner;
public class TestDemo {
   /* public static void main(String[] args){
        int n=1000;
        for(int i=100;i<n;i++){
            int a=i/100;
            int b=i/10%10;
            int c=i%10;
            if(i==a*a*a+b*b*b+c*c*c){
                System.out.println(i+"是水仙花");
            }
        }
    }*/
   public static void main(String[] args){
       Scanner sc=new Scanner(System.in);
       double num=sc.nextDouble();
       double cost=0;
       if(num<=0){
           System.out.println("Invalid input");
       }
       else if(num>20){
           System.out.println("the package cannot be shipped");
       }
       else{
           if(num<=1){
               cost+=3.5;
               System.out.print(cost);
           }
           else if(num<=3){
               cost+=5.5;
               System.out.print(cost);
           }
           else if(num<=10){
               cost+=8.5;
               System.out.printf("%.1f", cost);
           }
           else if(num<=20){
               cost+=10.5;
               System.out.printf("%.1f", cost);
           }
       }
   }
}
